The U.S. Open is more than just the matches, it's an experience. Each day, we'll highlight one part of what makes the Open the Open.

The eyes are the windows to the soul, Shakespeare wrote. In the tennis tempest that is the U.S. Open, pros armed with trained eyes and long lenses engage in visual soul searching.

The heights and depths of emotion players experience at the Open are frame-by-frame studies in the pits. Tennis photographers—along with linespeople and ball kids—are among the closest to the action from their positions in the photo pit, preparing, like the players, for that game-changing shot.

Veteran photographer Melchior DiGiacomo, who is shooting his 42nd U.S. Open this week and may be the only tennis photographer whose work has been displayed in the Museum of Modern Art in New York City as well as Time, Newsweek, Sports Illustrated, and the New York Times, says the job is much more than capturing forehands and backhands. DiGiacomo aims to fill the frame with passion.

"Every photographer looks for one thing: Powerful emotion,” says DiGiacomo, whose image of Chris Evert was embedded on her iconic Wilson racquet for many years. “There’s a lot of pain out there on that court. In football you don’t see it because the players wear masks, in tennis the pain, the emotion, it’s on their faces. I’m working on a book called ‘Existential Tennis’ and there’s not one action shot in the book, it’s all shots taken between points because emotion is powerful stuff.”

Photographers, like fans, have their favorite players to follow, though their choices are often based on aesthetic appeal and emotional expression rather than won-loss records.

“Serena is one of my favorites to shoot because Serena shows you the passion, the emotion, the temper, the fight, the joy,” says Italian photographer Angelo Tonelli, who has shot the U.S. Open every year since 1974. “Djokovic is another favorite because he reveals his emotions, he lets you inside his head and heart to see how he is feeling and thinking.”

When champions push past pain barriers in five-set struggles, character can be revealed. Longtime photographer Luigi Serra cites the images he shot of Pete Sampras overcoming cramps and on-court vomiting in his dramatic five-set triumph over Alex Corretja in 1996 as indelibly stamped in his mind.

“The Sampras-Corretja match was unforgettable,” Serra said. “The guys are cramping, Sampras has puke coming out of his mouth and he’s fighting with everything inside him. I will never forget that one.”

Sometimes, inaction—capturing the power of closure—can often be more dramatic that shooting action.

“Every last match is an important shot,” Tonelli says. “Agassi’s last match had such tremendous emotion and that’s a reason why you see so many photographers at Clijsters’ matches this year: Each match could be her last one and you want to be there to shoot it because of what she means to tennis and to people.”

While tennis writers can always retreat to the safe haven of the media workroom to watch matches in air-conditioned comfort, photographers—some of whom packing gear heavier than a couple of stocked racquet bags—trudge through the sticky, thick August air and feel the physicality of the game each day.

“It’s a physical, demanding job,” says New York City-based photographer Ed Goldman, who is shooting his 25th U.S. Open. “There are 15 courts to cover with five matches on most of them, it can be very hot, you could be carrying a lot of heavy gear and you’re fighting heavy crowds to get to where you need to be. I’m 72 now and I’ll be honest: I don’t run around as much as I used to. But it’s also an incredible thrill. You’ve got the best seat in the house, a few feet away from some of the greatest athletes in the world, the energy is tremendous, and every year we reconnect with old friends you’ve seen for 20 or 30 years.”

Understanding relationships and the interaction between athlete and audience can create compelling images.

"Ilie Nastase was playing Johan Kriek and there was a guy all the way up in the cheap seats, no shirt, pants rolled up to his knees and three large cups obviously filled with beer. Every time Kriek tossed the ball to serve this guy would scream at the top of his lungs ‘Come on Nastaseee!’", DiGiacomo recalls. "After the fifth or sixth time, Kriek had enough and says to the chair umpire ‘Can’t you do something about that guy yelling?’ The umpire said something you don’t say to madman: ‘I’m an umpire not an usher.’ So Kriek goes back to serve, the guy yells out “Come on Nastaseee!’ again and Kriek whacks the ball up at the guy and tells the umpire, ‘If you don’t do something about that guy, I will!’

With that Nastase walks up to the net, pokes Kriek in the chest with an index finger, makes a sweeping gesture toward the crowd and he says, ‘Look, for 15 years they’re all against me. You only got one against you!’ It was the greatest line and Kriek started laughing so hard he was almost in tears. I was one of the only photographers out there to hear it, I ran up to the press box and told [former New York Times sports editor] Neil Amdur the story and he ran it.”

Technology has changed players' and photographers' equipment. The digital age means photographers who once shot 40 photos of a match with regular film can now shoot 400 or 4,000 shots per match—and delete the unwanted images immediately as well. If you scan the photo pit immediately after a brilliant winner or dramatic point, you'll often see photographers looking down at their cameras—they're checking to see if they got the shot. The speed of the game and speed at which it is shot have changed dramatically since the days when the Open was contested on clay at nearby Forest Hills, as the Open Era has evolved into the Visual Age.

“If you had a nickel for every cell phone on the U.S. Open grounds, you could retire,” DiGiacomo says. “The biggest change in tennis photography from when I began in the old days is everyone is taking pictures now. When match point comes or when Roger Federer walks off the practice court you see cell phones raised. The world is becoming visually more literate, and for me that’s important because images can teach you and they can touch you."